hello, im having some troubles with my swap. im swapping a 97 3.9 v6 out of a dakota, to a 94 v8 5.2 318, also out of a dakota. but heres my problem now and i cannot get it figured out so someone PLEASE help! okay the tranny i have is manual. the new motor im putting in (the v8) was out of an automatic. the input shafts from the auto trannies and the manual trannies were the same i know, but i know the manuals used a pilot bearing and the autos didnt. well since the v8 i have was originally a auto, the hole in the back of the crank is smaller, (because it didnt use a pilot bearing.) therefore, a pilot bearing will not fit in the hole because the hole is only big enough for the shaft. WHAT DO I DO??

 

What diameter is the crank?

Looking at Rockauto, there are two sizes for both the 3.9 and the 5.2. One is 1.8" in diameter and the other 1".

 

I don't understand this part. The input shaft for the automatic fits inside the torque converter, not in the back of the crankshaft. And the nub on the converter that fits into the crank looks nothing like the end of the manual transmission's input shaft.

AFAIK, there aren't different cranks for manual and automatic.

 

I think the clutch engages into the back of the crank/flexplate assembly to hold a true center, where the convertor bolts to the flexplate in 3 (or 4?) places and center is implicit. But that's my guess.

 

That's all true. There is a "button" on the end of the converter that centers it on the crankshaft, but it fits into the pilot bearing hole in place of the pilot bearing, so it's much larger diameter than the pilot on the manual input shaft.

 

well okay i may have worded it wrong, but basically the pilot bearing hole in the automatic is smaller than the pilot bearing hole in the manual. so what do i do for a pilot bearing???

 

It's the year of the 5.2 that's causing the problem.

LA and Magnum engines use different sized pilot bushings.

There is also a "sleeve" available.

 

The '94 engine the OP is installing is a Magnum engine. Last year for the LA engine was in '91.

 

It should be a Magnum. Who knows for sure.

How else to explain the crankshaft?

 

Very simple. If it has TBI it's a LA...MPI it's a Magnum and IIRC the intakes are not interchangeable between the 2 engines but could be wrong on that account.